Which of the following is NOT considered a primary class of anti-hypertensive agents?

The correct identification of anti-hypertensive agents includes classes that are foundational in the management of hypertension. Thiazides, ACE inhibitors (ACEI), and calcium channel blockers are all primary classes widely recognized for their efficacy in lowering blood pressure and are frequently utilized as first-line treatments.

Thiazides are effective diuretics that help decrease blood volume and vascular resistance. ACE inhibitors are pivotal in interfering with the renin-angiotensin-aldosterone system, reducing blood pressure by relaxing blood vessels. Calcium channel blockers act by inhibiting calcium entry into cells of the heart and blood vessels, leading to vasodilation and lower blood pressure.

In contrast, alpha-agonists are generally not considered a first-line option for managing hypertension. While they can be useful in treating certain patients, their use is often more limited or as adjunctive therapy rather than foundational. This makes them less central in guidelines for antihypertensive therapy, hence classifying them as not being a primary class of agents for hypertension management.